TWI504594B - Process for the epoxidation of olefins - Google Patents

Description

Method for epoxidizing olefins

This invention relates to a process for the preparation of epoxidized olefins using peroxides, particularly with regard to epoxidation in a stream reactor and to enhance the selectivity of olefin epoxidation.

There are many ways to epoxidize unsaturated olefins, as described in Ullmann's Encyclopedia of Industrial Chemistry (Section: Epoxides, Wiley-VCH; 2000), with olefins via peroxyhydroxy acid, hydrogen peroxide, halogenated alcohol or The epoxidation reaction is carried out by molecular oxygen or the like. Epoxidized dienes are often epoxidized with peroxy hydroxy acid, such as peracetic acid; U.S. Patent No. 2716123 A (1955, UCC) discloses the instillation of 25.5% peracetic acid at 20-40 ° C for 2-3 hours. In the diene compound of the acetone solvent, after further reacting for 11-16 hours, the alicyclic diene compound of Formula 1, Formula 3, Formula 5, Formula 7, and Formula 9 can be epoxy-formed into Formula 2, Formula 4, and Formula. 6. The alicyclic diepoxides of formula 8 and formula 10 in yields of 85.5%, 84%, 85.4%, 95% and 79%, respectively.

British Bulletin GB735974 A (1955, UCC) discloses peracetic acid produced by oxidation of acetaldehyde to epoxidize Formula 11 to Formula 12. U.S. Patent No. 3,725,661 A (1966, Ciba) discloses that it can be prepared by injecting 42% peracetic acid at 30 ° C into benzene containing a dialkylate of formula 13 and sodium acetate in one hour, and continuing the reaction at 30 ° C for 4 hours. The diepoxide of formula 14 is obtained. Japanese Laid-Open Patent Publication No. 2006-188476 A (2006, Daicel) discloses a process for preparing a high-purity alicyclic diepoxide by reacting at a moisture content of 0.8 wt% of peracetic acid at 30 ° C for 3 hours. The alicyclic diene of formula 15 is epoxidized to the alicyclic diepoxide of formula 16.

U.S. Patent No. 8,697,895 B2 (2014, DOW) discloses the use of a titanium silicate rock-1 (TS-1) catalyst for epoxidizing propylene, using methanol as a solvent, and a non-reactive cosolvent. Solubility solubility parameter δ _D =0.4-1.0, polarity parameter δ _P =0.0-0.5 and hydrogen bond parameter δ _H =0.0-0.3, the use of this cosolvent can reduce the amount of methanol solvent used, thus reducing alcoholysis; Since the co-solvent can be separated from the moisture layer, and the by-product is mostly soluble in the water layer, the organic phase can be refluxed back to the reaction without the problem of accumulation of by-products, and the subsequent recovery process is simplified; the epoxy product can enter the organic phase. A non-reactive co-solvent that reduces the chance of product clogging the pores of the catalyst and prolongs its life. EU publication EP 2462130 B1 (2013, DOW) also uses epoxidized propylene with TS-1 catalyst, using methanol as solvent, and with non-reactive cosolvent, the solubility parameter of the cosolvent is close to that of propylene oxide product, which helps It reduces the amount of methanol solvent used, reduces alcoholysis by-products, increases the selectivity of epoxy products, extends catalyst life, and simplifies subsequent recovery processes.

In the traditional batch process, when olefin epoxidation is carried out with peroxide, dripping The conditions of the peroxide must be carried out at a low temperature and for a long period of time. The larger the reactor is used, the longer the time required for the dropwise addition, and the more difficult the reaction temperature is to control, which is likely to cause safety problems. Patent cooperation agreement PCT/EP2001/003875, Japanese publication patent JP 5163921 B2, Japanese laid-open patent JP 2009-256217 A and JP 2009-263240 A disclose epoxidation of olefins in a microreactor to provide a safer A method of continuous production. Among them, Japanese Laid-Open Patent Publication No. 2009-263240 A describes the oxidation of acetaldehyde in a microreactor using oxygen and a cobalt catalyst, and distillation to obtain a peracetic acid having a concentration of about 40%, and then using the peracetic acid at 35 ° C. In the stainless steel pipe having a diameter of 0.26 mm, the aliphatic diolefin compound of the formula 1 was epoxidized to obtain an aliphatic diepoxide of the formula 2 in a yield of 79%.

In the reaction of the peroxide epoxidized olefins, in order to reduce the side reaction of the epoxide hydrolysis, it is necessary to carry out the reaction at a low temperature and for a long period of time, which greatly reduces the productivity. Campanella, A. & Baltanás, MA studies on the hydrolysis of peracetic acid epoxidized vegetable oils (Chemical Engineering Journal 2006, 118, 141-152; Latin American Applied Research 2005, 35, 211-216 and 205-210), summarizing the substances that cause hydrolysis It is peracetic acid, acetic acid, protic acid, water and hydrogen peroxide. The hydrolysis reaction is related to protonic acid. Therefore, the pH value of the acetate or phosphate buffer is generally added, or the anhydrous peracetic acid is prepared by the acetaldehyde oxidation method, avoiding the protonic acid, water and Hydrogen peroxide causes a problem of hydrolysis of the epoxy compound, but it still does not solve the problem of hydrolysis of the epoxy compound by peracetic acid and acetic acid.

In the reaction of epoxidizing olefins with peroxides, the conversion and selectivity are not easy to balance, especially in the epoxidation reaction of diolefins. Under the high conversion reaction conditions, although the content of monoepoxide in the product is low, However, the selectivity of the hydrolysis reaction is relatively high; conversely, under the conditions of low hydrolysis, for example, conditions of low temperature or low reactant concentration, there is a problem that the selectivity of the monoepoxide is high.

The inventors of the present invention have successfully developed an epoxidized olefin having a low hydrolysis amount and high selectivity, particularly for preparing an alicyclic diepoxide. The method comprises the following steps: selecting a suitable solvent according to the solubility parameter, and epoxidizing the olefin in the reactor with a peroxide.

The present invention relates to a process for the epoxidation of olefins comprising reacting a peroxide with a olefin in a reactor having a solubility parameter δ _{T, a solvent} and δ _{H, a solvent} , and a ring in the presence of a _solvent The oxygen product has a solubility parameter δ _{T, product} and δ _{H, product} , where: δ _{T, product} -6 δ _{T, solvent} δ _{T, product} +6; and δ _{H, product-} 6 δ _{H, solvent} .

The solvent is selected according to the solubility parameter, and is often used for polymer composition, for example, coating composition, polymer processing and upgrading, elastomer industry and additives. The concept of solubility parameters was first proposed by Hildebrand JH (J. Am. Chem. Soc. 1916, 38, 1452-1473), and it is believed that the square root of the cohesive energy density of a substance can indicate the strength of interaction between liquid molecules. In 1967, Hansen CM established a three-dimensional solubility parameter system based on the original structure in the doctoral thesis, the so-called HSP (Hansen Solubility Parameters). HSP consists of three dimensions: δ _D , δ _P and δ _H , which represent dispersive force, polarity and hydrogen bond, respectively. The sum of the squares of the three can be expressed as δ ² _T , ie δ _T =(δ ² _D +δ ² _P + δ ² _H ) ^1/2 . The method of calculating the solubility parameter of the system using the group contribution method, the method can refer to the detailed Hansen, Charles M.2007 Hansen solubility parameters: a user's handbook Boca Raton, Fla: CRC Press, and Krevelen, DWvan; Hoftyzer, PJ1976 Properties of... Polymers: Their Estimation and Correlation with Chemical Structure ; 2nd ed.; Elsevier: Amsterdam; New York.

In the study of the effect of solvents on the epoxidation reaction, Sapunov and Lebedev (Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiya i Khimicheskaya Tekhnologiya 1965, 8, 771-775) epoxidized the olefin with peracetic acid and found that the greater the alkalinity of the solvent, the rate of epoxidation The smaller the constant. Murray and Gu (J. Chem. Soc., Perkin Trans. 2 1993, 2203-2207) trans-ethyl cinnamate and cyclohexene with dioxirane Epoxidation reaction, found when The stronger the hydrogen bond of the solvent, the faster the reaction of the epoxidation of the dioxirane. Gisdakis and Rösch (Eur. J. Org. Chem. 2001, 719-723; J. Phys. Org. Chem. 2001, 14, 328-332.) and Shi et al. (J. Mol. Catal. A: Chem. 2005, 238 , 13-25.) By simulating the reaction mechanism of epoxidation of olefins by peroxyhydroxy acid, it is found that hydrogen bonds of proton hydrogen or solvent in the reaction system can reduce the potential energy of the transition state structure in the epoxidation reaction, thereby improving The rate of peroxyhydroxy acid epoxidation. However, none of the above studies proposed a solution to reduce the monomer content in the epoxidized diene and reduce the amount of hydrolysis.

The inventors of the present invention have found through extensive simulation calculations and experiments that olefin epoxidation is carried out by using a solvent, and the solubility parameter δ _{T of the solvent} is used in the reaction, _{and the solvent} is equal to or in the solubility parameter δ _{T of the} epoxy product _{, and the product} ± Within the range of 6, ie δ _{T, product-} 6 δ _{T, solvent} δ _{T, product} +6, and solvent solubility parameter δ _{H, solvent} equal to or greater than the solubility parameter δ _{H of the} epoxy product _{, product} -6, ie δ _{H, product-} 6 δ _{H, a solvent} , increases the selectivity of the epoxy product and reduces the selectivity of the hydrolysis reaction. Preferred solvent solubility parameter δ _{T, solvent} equal to or between the solubility parameter δ _{T of the} epoxy product _{, product} -6 to δ _{T, product} +3, ie δ _{T, product} -6 ≦ δ _{T, solvent} ≦ δ _{T, product} +3, and solvent solubility parameter δ _{H, solvent} equal to or greater than the solubility parameter δ _{H of the} epoxy product _{, product} -6, ie δ _{H, product-} 6 δ _{H, solvent} .

It is to be understood that any range of values recited in this specification is intended to include all sub-ranges For example, the range from "δ _{T, product} -6 to δ _{T, product} +3" includes the stated minimum value δ _{T, product} -6 and the stated maximum value δ _T, and all sub-ranges between _products +3 (eg from δ _{T, product} to -5.2 δ _{T, product} + _1.5, δ _{T, product} to -3.5 δ _{T, product} +0.8) and comprising the two values, i.e., comprising greater than or equal to δ _{T, the product} of the minimum -6 And a range equal to or less than δ _T, the maximum value of the _product +3. Because the ranges of values disclosed are continuous, they contain each value between the minimum and maximum values. Unless otherwise stated, the various numerical ranges indicated in this specification are approximate.

The solvent used in the epoxidation reaction of the present invention varies depending on the type of epoxidized olefin and the reaction conditions, and suitable solvents include aliphatic carboxylic acid esters, alcohols or alkyl substituted derivatives thereof. Biological, cyclic or aryl substituted derivatives, hydrocarbons or alkyl substituted derivatives thereof, halogen substituted derivatives, ketones or alkyl substituted derivatives thereof, nitrile or aryl substituted derivatives, ethers, miscellaneous a cyclic compound, or a mixture of one or more of the foregoing. For example, suitable solvents include aliphatic carboxylic acid esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate; methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, a straight or branched chain type such as octanol or an alkyl substituted derivative thereof; a cyclic or aryl substituted derivative such as cyclohexanol or benzyl alcohol; a linear or branched hydrocarbon such as hexane or octane or a An alkyl-substituted derivative; an alicyclic hydrocarbon such as cyclohexane or cycloheptane or an alkyl-substituted derivative thereof; an aromatic hydrocarbon such as benzene, naphthalene, toluene or xylene; or an alkyl-substituted aromatic hydrocarbon; Chlorinated hydrocarbons such as chloroform, chlorobenzene and dichlorobenzene; ketone derivatives such as acetone, methyl ethyl ketone and methyl isobutyl ketone; nitrile derivatives such as acetonitrile, propionitrile, butyronitrile and phenylacetonitrile; An ether compound such as ether; a heterocyclic compound such as dioxane or tetrahydrofuran. Among them, from the viewpoint of solubility of a peroxide and an olefin reactant which can be dissolved as an epoxidizing agent, and selectivity of an epoxy product, etc., the solvent is preferably acetonitrile, acetone, n-butanol, 2-butanol or isooctanol. And cyclohexanol, benzyl alcohol, methyl acetate, ethyl acetate, butyl acetate, chloroform, dioxane, tetrahydrofuran, etc., which may be used alone or in combination of two or more.

The reactor used in the present invention is not limited to any type of reactor. In an embodiment of the invention, the reactor is a microreactor. In another embodiment of the invention, the reactor may be a batch or continuous reactor, wherein the continuous reactor may be a flow reactor.

The flow reactor may be a commercially available flow type reactor made of, for example, Corning Inc. of ^{Advanced-Flow ® Reactor, Ehrfeld Mikrotechnik} BTS GmbH of ^{Modular MicroReaction System, Lonza FlowPlate ®,} ART ® plate reactors, Miprowa ®; Cetoni's Qmix ^® microreaction system; Chemtrix's LABTRIX ^® START, LABTRIX ^® S1, KILOFLOW ^® and PLANTRIX ^® ; Little Things Factory's HTM ^® , MR-LAB ^® , MR PILOT ^® and XXL ^® SERIES; Syrris's Asia ^® Flow Chemistry System YMC's KeyChem ^® , CYTOS-200 ^® and CYTOS-2000 ^® ; in addition, a self-contained flow reactor can also be used. The inner diameter of the flow reactor is not limited, and the general inner diameter ranges from 0.01 mm to 10 mm, and preferably ranges from 0.05 mm to 8 mm. The optimum range is from 0.1 mm to 5 mm, considering the difficulty in producing the reactor, the reaction efficiency, the productivity, and the like. The flow reactor can have multiple channels in a single channel, in parallel or in series.

The present invention relates to a process in which a peroxide epoxidizes an olefin, and thus the peroxide used in the present invention plays a role as an epoxidizing agent. The peroxides usable in the present invention include peroxyhydroxy acids, peroxyhydroxybenzoic acids, alkyl hydroperoxides, alkyl-substituted benzene hydroperoxides, ester-substituted benzene hydroperoxides, Heterocyclic hydroperoxides, which are suitable, include hydrogen peroxide, performic acid, peracetic acid, tertiary butyl peroxide, di(tertiary butyl peroxide), tetraamyl hydroperoxide, cumene Hydrogen peroxide, isobutylbenzene hydroperoxide, benzammonium peroxide, cyclohexanone peroxide, dicumyl peroxide, methylcyclohexyl hydroperoxide, tetrahydronaphthalene peroxide, naphthylethane hydrogen peroxide And butyl peroxybenzoate. Further, in view of industrial easiness, the epoxidizing agent used may be peracetic acid, tertiary butyl peroxide, and cumene hydroperoxide.

The amount of the peroxide used as the epoxidizing agent is not critical, and the preferred amount is determined by the amount of the olefin compound used. Generally, the equivalent ratio of the peroxide to the olefin compound is in the range of 0.5 to 3, preferably the equivalent ratio range. It is from 0.8 to 2.8, and the optimum equivalent ratio ranges from 1 to 2.6. When a flow reactor is used, the amount of peroxide used can also be determined by the volume ratio or flow rate ratio of the two phases in the reactor. Generally, the flow ratio of the peroxide solution to the solvent containing the olefin is in the range of 0.2 to 5; The flow rate ratio ranges from 0.5 to 4; the optimum flow rate ratio ranges from 0.8 to 3.

The peroxide used in the present invention may be commercially available or self-manufactured, as in the latter, the preparation thereof is not strictly limited, and the preparation method is, for example, Ullmann's Encyclopedia of Industrial Chemistry (Vol. 26, Section: Peroxy) Compounds, Organic, Wiley-VCH, 2012) can be made by oxidation of the corresponding carboxylic acids, aldehydes, oximes, esters and alkenes. The concentration of the peroxide which can be used in the present invention in the peroxide solution is not limited, and the weight percentage of the peroxide which can be used in the peroxide solution is in the range of 20 to 70% by weight, preferably 20 to 65% by weight. %, preferably 25 to 60% by weight. When the weight percentage of the peroxide is less than 20% by weight, the conversion rate of the epoxidation reaction is greatly lowered due to the insufficient amount; when the weight percentage of the peroxide is more than 70% by weight, the industrial production of the peroxide is not easy. And it is more dangerous.

The present invention can add a buffering solvent during the reaction. The buffer solvent to be used in the present invention is not limited, and may be an acetate or a phosphate, and a suitable one thereof includes sodium acetate, sodium dihydrogen phosphate, and sodium hydrogen phosphate. The conjugated metal ion can be replaced with other alkali metal or alkaline earth metal ions to form an acetate or a phosphate such as potassium acetate, potassium dihydrogen phosphate or potassium hydrogen phosphate. The amount of the buffer solution is not more than 5% by weight, preferably not more than 2% by weight.

The epoxidized object of the present invention is an olefin compound, and the method according to the present invention can be applied to all olefins. The olefin compound contains at least one double bond and may contain two or more double bonds. The double bond can be internal or end of the molecular structure. The olefin compound may be a cyclic compound such as cyclohexene, 4-ethylene-1-cyclohexene, 1-methyl-5-(1-methylvinyl)cyclohexene, dicyclopentadiene. , dicyclohexyl-3,3'-diene, 4-(cyclohex-3-en-1-ylmethyl)cyclohexene, 2,2-bis(3',4'-cyclohexene)propane 2,2-bis(cyclohexen-3-yl)propane and the above derivatives or mixtures.

The olefin compound is preferably an alicyclic or aromatic compound, for example, 3-cyclohexene-1-carboxylic acid, 3-cyclohexen-1-ylmethyl ester, 3-cyclohexene-1-carboxylic acid ,6-methyl-(6-methyl-3-cyclohexen-1-yl)methyl ester, 3-cyclohexene-1-carboxylic acid, 3-methyl-(3-methyl-3-ring Hexen-1-yl)methyl ester, 3-cyclohexene-1-carboxylic acid-4-methyl, (4-methyl-3-cyclohexen-1-yl)methyl ester, 3-cyclohexene 1-carboxylic acid-1-methyl-, (1-methyl-3-cyclohexen-1-yl)methyl ester, 3-cyclohexene-1-carboxylic acid-2-methyl, (2- Methyl-3-cyclohexen-1-yl)methyl ester, 3-cyclohexene-1-carboxylic acid, 3,4-dimethyl-, (3,4- Dimethyl-3-cyclohexen-1-yl)methyl ester, 3-cyclohexene-1-carboxylic acid, 1-(3-cyclohexen-1-yl)ethyl ester, 3-cyclohexene- 1-carboxylic acid, 1-(3-cyclohexen-1-yl)-1-methylethyl ester, bicyclo[2,2,1]hex-5-ene-2-carboxylic acid, 3-methyl , (3-methylbicyclo[2,2,1]hex-5-en-2-yl)methyl ester, 5-norbornene-2-carboxylic acid, ethylene diester, 1,6-hexanediol- Bis(norborn-2-ene-5-carboxylic acid), 3-cyclohexene-1-carboxylic acid, ethylene diester, 3-cyclohexene-1-carboxylic acid, 4-methyl-, 1,2 -ethylene diester, 3-cyclohexene-1-carboxylic acid, 4-methyl, 1-methyl-1,2-ethanediester, 3-cyclohexene-1-carboxylic acid, 6-A 1,1'-(1,6-hexanediyl)ester, 3-cyclohexene-1-carboxylic acid, 1,1'-[1,4-cyclohexanediyl bis(methene) ] ester, carbonic acid, C, C'-[1,4-cyclohexanediyl bis(methylene)]C, C'-bis(3-cyclohexen-1-ylmethyl) ester, oxalic acid 1,2-bis(3-cyclohexen-1-ylmethyl)ester, adipic acid, 1,6-bis(3-cyclohexen-1-ylmethyl) ester, maleic acid, double (6 -Methyl-3-cyclohexen-1-ylmethyl)ester, 1,4-cyclohexanedicarboxylic acid, 1,4-bis(3-cyclohexen-1-ylmethyl)ester, 1, 1,2,2-ethane tetracarboxylic acid, tetrakis(3-cyclohexen-1-ylmethyl)ester, 1,2,3,4-butanetetracarboxylic acid, tetrakis(3-cyclohexene) -1-ylmethyl)ester, bicyclo[2. 2.1]Hex-5-ene-2-carboxylic acid, 2,2'-[[2,2-bis[(bicyclo[2.2.1]hex-5-en-2-ylformyl)oxy]-) -1,3-propanediyl]ester, bicyclo[2.2.1]hex-5-ene-2-carboxylic acid, 2,2'-[[2,2-bis[(bicyclo[2.2.1] Hex-5-en-2-ylcarbonyl)oxy]-2-ethyl-1,3-propanediyl) ester, bis(cyclohex-3-enylmethyl)carbonate, bis[1] -(3-cyclohexene)ethyl]carbonate, diallyl 1,2-cyclohexanedicarboxylate, diallyl tetrahydrofurfurate, 1,2-cyclohexanedicarboxylic acid 1,2-bis(3-cyclohexen-1-ylmethyl)ester, 4-cyclohexene-1,2-dicarboxylic acid, 1,2-bis(3-cyclohexen-1-yl) Methyl)ester, poly[oxy(1-oxo-1,6-hexanediyl)], α-(3-cyclohexen-1-ylmethyl)-ω-[(3-cyclohexene- 1-ylcarboxylic acid)oxy]- and the above derivatives or mixtures.

The olefin compound may also be a compound containing an ether bond in the structure, for example, bis(cyclopent-2-enyl)ether, bis(cyclopent-3-enyl)ether, 4-(cyclohex-3- Alken-1-yl)methoxymethylcyclohexene, cyclohexene, 3,3'-[methane bisoxy]bis-, 4-(cyclohex-3-en-1-yloxymethoxy) Cyclohexene, ethylene glycol bis(2-cyclohexenyl) ether, isopropyl glycol bis(2-cyclohexenyl) ether, bis(3-cyclohexen-1-ylmethoxy)methane, methane, Bis(5-norbornene-2-ylmethoxy)-, bicyclo[2,2,1]hex-2-ene, 5,6-bis[(2-propen-1-yloxy)methyl )-, bisphenol A diallyl Ether, bisphenol F diallyl ether, cyclohexene, 4,4-bis[(2-cyclohexen-1-yloxy)methyl]-, tetrapropenyl pentaerythritol ether and the above derivatives or mixture.

The olefin compound may also be a compound containing a heterocyclic ring or an amino group in the structure, for example, 3-cyclohex-2-en-1-yl-2,4-dioxospiro[5.5]undec-9-ene. , spiro [m-dioxoindole-5,2'-[5]norbornene], 2-(5-norbornene-2-yl)-, bis[4-(diallylammonium)phenyl Methane, aniline, N,N-di-2-propenyl-4-(2-2-propenyloxy)- and the above derivatives or mixtures. The olefin compound may also be a compound containing citric acid or phosphoric acid in a structure, for example, cyclohexene, 4,4',4"-[(methylmethenyl)tris(oxyethyl)], Methane, tris(bicyclo[2.2.1]hex-5-en-2-ylmethoxy)methyl-, tris(cyclohex-3-enemethanol)phenyl decane, citric acid, tetra (3- Cyclohexene-1-ylmethyl)ester, 3-cyclohexene-1-methanol, 1,1',1"-phosphoric acid and the above derivatives or mixtures, triallyl isocyanurate.

In one embodiment of the invention, the olefinic compound is selected from the compounds listed in the following table:

The concentration of the olefins in the solution may be from 1 to 99% by weight, preferably from 10 to 90% by weight, most preferably from 20 to 80% by weight.

In one embodiment of the invention, the reaction temperature of the reaction is from 0 ° C to 110 ° C, preferably from 30 ° C to 100 ° C, and most preferably from 50 ° C to 100 ° C.

In an embodiment of the invention, the residence time of the reaction is from 10 seconds to 120 seconds. It is preferably 15 seconds to 100 seconds, preferably 20 seconds to 100 seconds.

In one embodiment of the present invention, the reaction back pressure is not limited, and the back pressure is the pressure required to control the solvent or reactant to the liquid phase at different temperatures of the solvent or reactant.

In one embodiment of the invention, the reaction may have a two or more epoxy molar selectivity of greater than or equal to 80%, preferably greater than or equal to 90, when the olefin reactant conversion is greater than or equal to 99%. %, the best system is greater than or equal to 95%.

In one embodiment of the invention, the reaction may have a monoepoxy molybdenum selectivity of less than or equal to 5%, preferably less than or equal to 3, when the olefin reactant conversion is greater than or equal to 99%. %, the best is less than or equal to 1.5%.

In an embodiment of the present invention, the reaction may have a hydrolyzable molar selectivity of less than or equal to 15%, preferably less than or equal to 10%, when the olefin reactant conversion rate is greater than or equal to 99%. The best system is less than or equal to 5%.

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention, and any modifications and variations which may be obtained without departing from the spirit of the invention are range.

GC and HPLC analysis

After the olefin epoxidation by the method of the present invention, the obtained product is prepared in 2-butanol and analyzed by gas chromatography (GC), and the integral area of each component is determined by the calibration line to determine the quality of each component. , converted to moles. The titration method for quantifying peracetic acid and hydrogen peroxide in peracetic acid solution is carried out according to the national standard "GB 19104-2008 peracetic acid solution" of the People's Republic of China. A method for the quantitative determination of peracetic acid, hydrogen peroxide and acetic acid by peracetic acid solution by high performance liquid chromatography (HPLC) is described in the literature "Analytical Chemistry October 2004, No. 32 In the method of volume, No. 10, pages 1329 to 1332, the integral area of each component is determined by the calibration curve.

GC analysis conditions

Device: PerkinElmer AutoSystem

Detector: Flame Ionization Detector (FID)

Column: Agilent Tech HP-1 0.320mm, length=50M, film=1.05 carrier gas: N ₂ 20psi

Injection port temperature: 220 ° C

Detector zone temperature: 280 ° C

HPLC analysis conditions

Device: Waters 600

Detector: Waters 2487 Dual λ.Absorbance Detector

Detection wavelength: 205nm

Column: YMC-Pack ODS C18 L=150mm, ID=6.0mm

Column temperature: 40 ° C

Mobile phase: Water:Acetonitrile=82:18 (v.v)

Mobile phase flow rate: 0.8mL/min

Selection rate calculation method

The olefin epoxidation olefin conversion rate, the monoepoxy compound molar selectivity, the diepoxide molar selectivity, and the hydrolyz molar selectivity are defined as follows. The olefin compound consumed by the reaction is considered to be a hydrolyzate when a non-corresponding monoepoxy compound or diepoxide is formed.

Molar selectivity of hydrolysate = 100% - (monoepoxy molybdenum selectivity) - (diepoxide molar selectivity)

Example 1

Place 1431 ml of acetic acid, 1646 ml of 50% by weight of hydrogen peroxide in a 12 liter glass reaction flask, keep the temperature below 45 ° C, add 280 ml of concentrated sulfuric acid dropwise over 90 minutes, add dropwise After the end, the mixture was stirred for another 30 minutes. The temperature was maintained at 45 ° C, the pressure was reduced to 10 Torr, and after distillation for 2 hours, the distillate was obtained as a peracetic acid solution. After the peracetic acid solution was titrated with a potassium permanganate solution and a sodium thiosulfate solution, it was found that the peracetic acid solution had a peracetic acid content of 58.5 wt% and a hydrogen peroxide content of 3.4 wt%. After the peracetic acid solution was analyzed by HPLC, it was found that the acetic acid content in the peracetic acid solution was 11.7% by weight.

The sodium peracetate solid was added to the above peracetic acid solution to prepare a peracetic acid solution containing 1.0% by weight of sodium acetate, and injected into a 1.0 ml glass gas-tight needle and mounted on a syringe pump at a flow rate of 6.65 μl per minute. 5.0 g of 3-cyclohexene-1-carboxylic acid, 3-cyclohexen-1-ylmethyl ester was mixed with 10.0 g of toluene, injected into another 1.0 ml glass gas-tight needle and mounted on a syringe pump. The flow rate was set to 8.35 microliters per minute.

The above two solutions were injected into a glass microreactor having an equivalent diameter of 0.2 mm and heated to 90 ° C for a reaction residence time of 40 seconds. After 10 minutes of reaction, a sample was analyzed by GC. The conversion of the diene reactant was 99.7%, the molar selectivity of the monoepoxide was 1.2%, the molar selectivity of the diepoxide was 95.8%, and the selectivity of the hydrolysis molar was 3.0%.

Example 2~5

The toluene in Example 1 was replaced with acetone, 2-ethylhexanol, benzyl alcohol and acetonitrile in each of Examples 2 to 5, and the results of GC analysis are shown in Table 1.

Comparative example 1~3

The toluene in Example 1 was replaced with cyclohexane, methanol and ethanol in Comparative Examples 1 to 3, respectively, and the results of GC analysis are shown in Table 1.

Example 6

A 58.5 wt% peracetic acid solution of Example 1 was added with an aqueous solution of sodium acetate to prepare a peracetic acid solution containing 1.0% by weight of sodium acetate and 43% by weight of peracetic acid, and injected into a 1.0 ml glass gas-tight needle and mounted on a syringe pump. The flow rate was set to 6.5 microliters per minute. 3.0 g of 3-cyclohexene-1-carboxylic acid, 3-cyclohexen-1-ylmethyl ester was mixed with 2.0 g of benzyl alcohol, injected into another 1.0 ml glass-tight needle and mounted on a syringe pump. The flow rate was set to 5.5 microliters per minute.

The above two solutions were injected into a glass microreactor having an equivalent diameter of 0.2 mm and heated to 90 ° C for a reaction residence time of 50 seconds. After 10 minutes of reaction, a sample was analyzed by GC. The conversion of the diene reactant was 99.6%, the molar selectivity of the monoepoxide was 0.7%, the molar selectivity of the diepoxide was 85.1%, and the selectivity of the hydrolysis molar was 14.2%.

Examples 7-8

The benzyl alcohol in Example 6 was replaced with a mixed solution of ethyl acetate and diethyl ether: toluene = 1:1 in Example 7 and Example 8, respectively, and the results of GC analysis are shown in Table 2.

Comparative Example 4~5

The benzyl alcohol in Example 6 was replaced with a mixed solution of a weight ratio of toluene: n-hexane = 1:9 and a mixed solution of a weight ratio of toluene: n-hexane = 1:1 in Comparative Example 4 to Comparative Example 5, respectively. The GC analysis results are shown in Table 2.

Example 9

A 58.5 wt% peracetic acid solution of Example 1 was added with an aqueous solution of sodium acetate to prepare a peracetic acid solution containing 1.0% by weight of sodium acetate and 42% by weight of peracetic acid, and injected into a 1.0 ml glass gas-tight needle and mounted on a syringe pump. The flow rate was set to 6.5 microliters per minute. 2.5 g of 3-cyclohexene-1-carboxylic acid, 3-cyclohexen-1-ylmethyl ester was mixed with 2.0 g of ethyl acetate, and injected into another 1.0 ml glass-tight needle and mounted in an injection. Pump, flow rate set to 5.5 microliters per minute.

The above two solutions were injected into a glass microreactor having an equivalent diameter of 0.2 mm and heated to 80 ° C for a reaction residence time of 50 seconds. After 10 minutes of reaction, a sample was analyzed by GC. The conversion of the diene reactant was 99.7%, the molar selectivity of the monoepoxide was 1.2%, the molar selectivity of the diepoxide was 98.7%, and the selectivity of the hydrolysis molar was 0.1%.

Example 10

A 58.5 wt% peracetic acid solution of Example 1 was added to an aqueous solution of sodium acetate to prepare a peracetic acid solution containing 1.0% by weight of sodium acetate and 42% by weight of peracetic acid, and injected into a 25 ml double syringe continuous syringe pump. The flow rate was set to 8.44 ml per minute. 250 g of 3-cyclohexene-1-carboxylic acid, 3-cyclohexen-1-ylmethyl ester was mixed with 200 g of ethyl acetate, and injected into another 25 ml double syringe continuous syringe pump. The flow rate was set to 7.16 ml per minute.

The above two solutions were injected into a flow reactor having an equivalent diameter of 1.34 mm and heated to 80 ° C for a reaction residence time of 50 seconds. After the reaction for 30 minutes, a sample was analyzed by GC. The conversion of the diene reactant was 99.9%, the molar selectivity of the monoepoxide was 0.3%, the molar selectivity of the diepoxide was 93.8%, and the selectivity of the hydrolysis molar was 5.9%.

Comparing results

Referring to Table 1, the δ _T and δ _H of the solvents of Examples 1 to 5 are in accordance with the specific range of the present invention, thus maintaining a low monoepoxy molybdenum selectivity and a low hydrolyzable molar selectivity at high olefin conversion. . The solvent of Comparative Example 1 did not satisfy the specific range of the present invention because δ _H did not cause the epoxidation reaction rate to be slow, so the conversion rate was low, and the molar selectivity of the monoepoxide was high. In Comparative Example 2 and Comparative Example 3, since δ _{T was} outside the specific range of the present invention, the solvent-protecting resin was prevented from being degraded by hydrolysis, so that the hydrolysis selectivity was high at the same time as high conversion.

Referring to Comparative Example 4 and Comparative Example 5 in Table 2, even at a longer reaction residence time, the conversion rate failed to reach 99% or more, and the molar selectivity of the monoepoxide was high, and the hydrolysis molar selectivity was biased. High situation.

Referring to Example 9 and Example 10, the flow reactor to which the present invention can be applied to the inner diameters of different passages is explained, and has the utility value of industrial production.

Therefore, the example in which the solvent is selected according to the solubility parameter of the present invention has a low monoepoxy selectivity and a low hydrolysis selectivity while maintaining a high olefin conversion rate.

Claims (15)

A process for the epoxidation of olefins comprising reacting a peroxide with a olefin in a reactor in the presence of a solvent having a solubility parameter δ _{T, a solvent} and δ _{H, a solvent} and the resulting epoxy product having solubility The parameter δ _{T, product} and δ _{H, product} , wherein: δ _{T, product} -6 ≦ δ _{T, solvent} ≦ δ _{T, product} +6; and δ _{H, product} -6 ≦ δ _{H, solvent} . The method of claim 1, wherein δ _{T, product} -6 ≦ δ _{T, solvent} ≦ δ _{T, product} +3; and δ _{H, product} -6 ≦ δ _{H, solvent} . The method of claim 1, wherein the peroxide is a peroxy hydroxy acid. The method of claim 1, wherein the reactor is a stream reactor. The method of claim 4, wherein the flow reactor is a microreactor. The method of claim 5, wherein the flow reactor has a channel inner diameter of from 0.01 mm to 10 mm. The method of claim 5, wherein the flow reactor has a plurality of channels in a single channel, in parallel or in series. The method of claim 5, wherein the peroxide has a flow rate of 0.2 to 5 to the olefin. The method of claim 1, wherein the equivalent ratio of the peroxide to the olefin is from 0.5 to 3. The method of claim 1, wherein the buffering solvent is added to the reaction process in an amount of less than or equal to 5% by weight. The method of claim 1, wherein the peroxide is added to the reactor in the form of a peroxide solution. The method of claim 1, wherein the olefin is an alicyclic olefin. The method of claim 1, wherein the concentration of the olefin in the solution is from 1 to 99 by weight. %. The method of claim 1, wherein the reaction temperature of the reaction is from 0 ° C to 110 ° C. The method of claim 1, wherein the residence time of the reaction is from 10 seconds to 120 seconds.